Why bother? You can buy them at your nearest magic shop, or herbalists. In old times we made our own. Much of that skill has been lost, simply because it is no longer necessary. But if you insist, there are many books on the subject.

A good beginning book on the subject of making potions or various sorts is "The Complete Book of Incense, Oils and Brews" by Scott Cunningham. This book gives some safe, non-toxic potions that can be useful, and it gives some basic instruction on how to create such things.

I would also suggest "Cunningham's Encyclopedia of Magical Herbs" also by Scott Cunningham as a beginning book to learn about different herbs and their magical uses.